package main

import (
	"bytes"
	"encoding/json"
	"image"
	"image/png"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/BurntSushi/toml"
)

// newTestServer builds a Server over fresh temp content/output dirs with a
// couple of posts, runs one build, and returns it.
func newTestServer(t *testing.T) (*Server, string, string) {
	t.Helper()
	content := t.TempDir()
	output := t.TempDir()

	writePNG(t, filepath.Join(content, "foo.png"))
	if err := os.WriteFile(filepath.Join(content, "foo.toml"),
		[]byte("caption = \"Foo\"\ndate = \"2026-01-02\"\ntags = [\"berlin\", \"street\"]\n"), 0600); err != nil {
		t.Fatal(err)
	}
	writePNG(t, filepath.Join(content, "bar.png")) // no sidecar

	g := NewGenerator(content, output, "http://x", "A", "@a", "bio", "", "f", "s", "m", 60, viewTimeline)
	if err := g.Build(); err != nil {
		t.Fatalf("initial build: %v", err)
	}
	s := NewServer("0", content, output, false, g, nil)
	// Make rebuilds a no-op; tests call Build explicitly when they need to
	// assert on generated output, so no background goroutine races teardown.
	s.rebuildHook = func() {}
	return s, content, output
}

func writePNG(t *testing.T, path string) {
	t.Helper()
	f, err := os.Create(path)
	if err != nil {
		t.Fatal(err)
	}
	defer f.Close()
	if err := png.Encode(f, image.NewRGBA(image.Rect(0, 0, 2, 2))); err != nil {
		t.Fatal(err)
	}
}

func form(v url.Values) *http.Request {
	r := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(v.Encode()))
	r.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	return r
}

// multipartForm builds a multipart/form-data request, as a browser's FormData
// does — the content type the manage handlers must parse, not just urlencoded.
func multipartForm(fields map[string]string) *http.Request {
	var b bytes.Buffer
	mw := multipart.NewWriter(&b)
	for k, v := range fields {
		mw.WriteField(k, v)
	}
	mw.Close()
	r := httptest.NewRequest(http.MethodPost, "/", &b)
	r.Header.Set("Content-Type", mw.FormDataContentType())
	return r
}

func readMeta(t *testing.T, content, slug string) PhotoMeta {
	t.Helper()
	var m PhotoMeta
	if _, err := toml.DecodeFile(filepath.Join(content, slug+".toml"), &m); err != nil {
		t.Fatalf("decode %s: %v", slug, err)
	}
	return m
}

func TestResolveSlug(t *testing.T) {
	s, _, _ := newTestServer(t)
	cases := map[string]bool{
		"foo":        true,
		"bar":        true,
		"nope":       false,
		"../server":  false,
		"foo/../foo": false,
		".trash":     false,
		"":           false,
		"sub/foo":    false,
	}
	for slug, want := range cases {
		if _, ok := s.resolveSlug(slug); ok != want {
			t.Errorf("resolveSlug(%q) = %v, want %v", slug, ok, want)
		}
	}
}

func TestHandleEdit(t *testing.T) {
	s, content, _ := newTestServer(t)

	rec := httptest.NewRecorder()
	s.handleEdit(rec, form(url.Values{
		"slug":    {"foo"},
		"caption": {"New caption"},
		"date":    {"2020-05-06"},
		"tags":    {"Paris, , night"},
	}))
	if rec.Code != http.StatusOK {
		t.Fatalf("edit: code=%d body=%s", rec.Code, rec.Body)
	}
	m := readMeta(t, content, "foo")
	if m.Caption != "New caption" || m.Date != "2020-05-06" {
		t.Errorf("caption/date not saved: %+v", m)
	}
	if strings.Join(m.Tags, ",") != "paris,night" { // lowercased, empty dropped
		t.Errorf("tags = %v, want [paris night]", m.Tags)
	}

	// Bad date rejected.
	rec = httptest.NewRecorder()
	s.handleEdit(rec, form(url.Values{"slug": {"foo"}, "date": {"06-05-2020"}}))
	if rec.Code != http.StatusBadRequest {
		t.Errorf("bad date: code=%d, want 400", rec.Code)
	}

	// Unknown slug rejected (and cannot escape content dir).
	rec = httptest.NewRecorder()
	s.handleEdit(rec, form(url.Values{"slug": {"../evil"}, "date": {"2020-01-01"}}))
	if rec.Code != http.StatusNotFound {
		t.Errorf("unknown slug: code=%d, want 404", rec.Code)
	}
}

func TestHandleBulkTags(t *testing.T) {
	s, content, _ := newTestServer(t)

	// Add to bar (no sidecar yet) and foo (already has tags).
	rec := httptest.NewRecorder()
	s.handleBulkTags(rec, form(url.Values{"slugs": {"foo,bar"}, "add": {"aqua, berlin"}}))
	if rec.Code != http.StatusOK {
		t.Fatalf("bulk add: code=%d body=%s", rec.Code, rec.Body)
	}
	foo := readMeta(t, content, "foo")
	// berlin already present → not duplicated; aqua appended.
	if got := strings.Join(foo.Tags, ","); got != "berlin,street,aqua" {
		t.Errorf("foo tags = %q, want berlin,street,aqua", got)
	}
	if got := strings.Join(readMeta(t, content, "bar").Tags, ","); got != "aqua,berlin" {
		t.Errorf("bar tags = %q, want aqua,berlin", got)
	}

	// Remove across both.
	rec = httptest.NewRecorder()
	s.handleBulkTags(rec, form(url.Values{"slugs": {"foo,bar"}, "remove": {"berlin"}}))
	if rec.Code != http.StatusOK {
		t.Fatalf("bulk remove: code=%d", rec.Code)
	}
	if got := strings.Join(readMeta(t, content, "foo").Tags, ","); got != "street,aqua" {
		t.Errorf("foo tags after remove = %q, want street,aqua", got)
	}

	// Empty add+remove is a 400.
	rec = httptest.NewRecorder()
	s.handleBulkTags(rec, form(url.Values{"slugs": {"foo"}}))
	if rec.Code != http.StatusBadRequest {
		t.Errorf("empty bulk: code=%d, want 400", rec.Code)
	}
}

func TestHandleDeleteMovesToTrashAndPrunes(t *testing.T) {
	s, content, output := newTestServer(t)

	// Pre-condition: foo's rendition and page exist.
	for _, p := range []string{"thumbs/foo.jpg", "images/foo.png", "photo/foo/index.html"} {
		if _, err := os.Stat(filepath.Join(output, p)); err != nil {
			t.Fatalf("expected %s before delete: %v", p, err)
		}
	}

	rec := httptest.NewRecorder()
	s.handleDelete(rec, form(url.Values{"slug": {"foo"}}))
	if rec.Code != http.StatusOK {
		t.Fatalf("delete: code=%d", rec.Code)
	}
	var res map[string]int
	json.Unmarshal(rec.Body.Bytes(), &res)
	if res["deleted"] != 1 {
		t.Errorf("deleted = %d, want 1", res["deleted"])
	}

	// Source files moved out of content/ ...
	if _, err := os.Stat(filepath.Join(content, "foo.png")); !os.IsNotExist(err) {
		t.Error("foo.png should be gone from content")
	}
	// ... and into .trash/ (timestamp-suffixed).
	trash, _ := os.ReadDir(filepath.Join(content, ".trash"))
	var png, tml bool
	for _, e := range trash {
		if strings.HasPrefix(e.Name(), "foo.") && strings.HasSuffix(e.Name(), ".png") {
			png = true
		}
		if strings.HasPrefix(e.Name(), "foo.") && strings.HasSuffix(e.Name(), ".toml") {
			tml = true
		}
	}
	if !png || !tml {
		t.Errorf("trash missing files: png=%v toml=%v entries=%v", png, tml, trash)
	}

	// The handler rebuilds asynchronously; run a deterministic build, then
	// confirm the prune removed foo's output and kept bar's.
	if err := s.generator.Build(); err != nil {
		t.Fatal(err)
	}
	for _, p := range []string{"thumbs/foo.jpg", "images/foo.png", "photo/foo"} {
		if _, err := os.Stat(filepath.Join(output, p)); !os.IsNotExist(err) {
			t.Errorf("%s should have been pruned", p)
		}
	}
	if _, err := os.Stat(filepath.Join(output, "thumbs/bar.jpg")); err != nil {
		t.Errorf("bar's thumb should survive: %v", err)
	}
}

// TestMultipartBodies guards the regression where the manage handlers used
// r.ParseForm (urlencoded only) and silently ignored the multipart bodies that
// browsers send via FormData, returning 200 with deleted:0 / no change.
func TestMultipartBodies(t *testing.T) {
	s, content, _ := newTestServer(t)

	// Edit via multipart.
	rec := httptest.NewRecorder()
	s.handleEdit(rec, multipartForm(map[string]string{
		"slug": "foo", "caption": "Multipart", "date": "2021-02-03", "tags": "x,y",
	}))
	if rec.Code != http.StatusOK {
		t.Fatalf("multipart edit: code=%d", rec.Code)
	}
	if m := readMeta(t, content, "foo"); m.Caption != "Multipart" || strings.Join(m.Tags, ",") != "x,y" {
		t.Errorf("multipart edit not applied: %+v", m)
	}

	// Delete via multipart actually moves the file.
	rec = httptest.NewRecorder()
	s.handleDelete(rec, multipartForm(map[string]string{"slug": "bar"}))
	var res map[string]int
	json.Unmarshal(rec.Body.Bytes(), &res)
	if res["deleted"] != 1 {
		t.Fatalf("multipart delete: deleted=%d, want 1 (body=%s)", res["deleted"], rec.Body)
	}
	if _, err := os.Stat(filepath.Join(content, "bar.png")); !os.IsNotExist(err) {
		t.Error("bar.png should have moved to trash")
	}
}

func TestCSRFGuard(t *testing.T) {
	s, _, _ := newTestServer(t) // generator.baseURL == "http://x"

	// A cross-site Origin is refused before any mutation runs.
	r := form(url.Values{"slug": {"foo"}})
	r.Header.Set("Origin", "http://evil.example")
	rec := httptest.NewRecorder()
	s.handleDelete(rec, r)
	if rec.Code != http.StatusForbidden {
		t.Errorf("cross-site Origin: code=%d, want 403", rec.Code)
	}

	// Sec-Fetch-Site: cross-site is likewise refused.
	r = form(url.Values{"slug": {"foo"}})
	r.Header.Set("Sec-Fetch-Site", "cross-site")
	rec = httptest.NewRecorder()
	s.handleDelete(rec, r)
	if rec.Code != http.StatusForbidden {
		t.Errorf("Sec-Fetch cross-site: code=%d, want 403", rec.Code)
	}

	// Same-origin is allowed through (no slugs → deletes nothing, 200).
	r = form(url.Values{})
	r.Header.Set("Sec-Fetch-Site", "same-origin")
	rec = httptest.NewRecorder()
	s.handleDelete(rec, r)
	if rec.Code != http.StatusOK {
		t.Errorf("same-origin: code=%d, want 200", rec.Code)
	}

	// A matching Origin is allowed.
	r = form(url.Values{})
	r.Header.Set("Origin", "http://x")
	rec = httptest.NewRecorder()
	s.handleDelete(rec, r)
	if rec.Code != http.StatusOK {
		t.Errorf("matching Origin: code=%d, want 200", rec.Code)
	}
}

func TestHandleListPhotos(t *testing.T) {
	s, _, _ := newTestServer(t)
	rec := httptest.NewRecorder()
	s.handleListPhotos(rec, httptest.NewRequest(http.MethodGet, "/api/photos", nil))
	if rec.Code != http.StatusOK {
		t.Fatalf("list: code=%d", rec.Code)
	}
	var photos []photoJSON
	if err := json.Unmarshal(rec.Body.Bytes(), &photos); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if len(photos) != 2 {
		t.Fatalf("got %d photos, want 2", len(photos))
	}
	var foo *photoJSON
	for i := range photos {
		if photos[i].Slug == "foo" {
			foo = &photos[i]
		}
	}
	if foo == nil {
		t.Fatal("foo not in list")
	}
	if foo.Thumb != "/thumbs/foo.jpg" || foo.URL != "/photo/foo/" {
		t.Errorf("foo paths wrong: %+v", foo)
	}
	if strings.Join(foo.Tags, ",") != "berlin,street" {
		t.Errorf("foo tags = %v", foo.Tags)
	}
}